Civics education in the United States faces a crisis because of a drift away from the ideals held by the nation's founders, U.S. Supreme Court Justice Antonin Scalia said Friday in Chicago.

Scalia said that among his concerns is the removal of religious ideals from public education.

"Let me make clear that I am not saying that every good American must believe in God," Scalia said in a speech at the Union League Club. "What I am saying, however, is that it is contrary to our founding principles to insist that government be hostile to religion. Or even to insist, as my court, alas, has done, that government cannot favor religion over nonreligion.

"It is not a matter of believing that God exists, though personally I believe that," Scalia said. "It is a matter of believing, as our founders did, that belief in God is very conducive to a successful republic."

Scalia spoke to a large audience at the club's 126th annual George Washington's Birthday Gala.

A University of Chicago law professor in the late 1970s and early 1980s, Scalia is considered one of the leading intellectuals of the high court's conservative wing.

Scalia, 77, is the court's longest-serving justice, taking his seat in 1986. In his talk Friday he lived up to his reputation as a quick wit and was interrupted frequently by laughter and applause. He weighed in on the relative merits of Chicago-style pizza (which he described as "tomato pie," to a chorus of boos) versus New York pies.

But his comments often struck a somber tone.

"You know what I worry most about is ... the decline of the republican spirit," Scalia said softly during a brief question-and-answer session.

"It doesn't exist in our people with a vigor that used to exist. That's what I'm most worried about, that we're going to become just another, I don't know, another undemocratic, politician-run state. Which our framers would never have supported. That's why I think education in democracy, education in republicanism, is so important."

Scalia demurred when asked whether the country has passed a "tipping point" that would put it on a downward curve.

"The framers were very worried about whether democracy could last very long. The game isn't up yet, 200 years is a good long time," he said.

"(But) I don't think we can be too cocky about America always being America. It's going to change unless the people have the same determination to preserve liberty that the framers had."